Living in the city won’t allow you to see fireflies because of bright lights. Firefly watching is one of the interesting things to do when you’re in Puerto Princesa. The boat rental is just Php 600 ( For 2 – 4 people). Someone will be rowing the boat for you (and will give you a background about the river, fireflies and planktons), they’re youth volunteers who want to preserve the Iwahig River. Riding small boats may be scary but let me tell you, the waters are very calm.
You can read more about our experience here: http://www.pinoytravelr.com/blog/firefly-watching-in-iwahig-river/